This invention relates to a chair arranged to support a person thereon such that the person may be inverted for therapeutic purposes.
Inversion devices such as inversion chairs and tables are known for therapeutic purposes and particularly for the treatment of a person""s spine to relieve pain and tension from the spine by inverting the person supported thereon. These devices generally comprise a frame and a support pivotally mounted on the frame such that a person may be supported thereon for pivotal movement between an upright position and an inverted position. The devices generally require a person to pivot themselves in a rearward direction from the upright position to the inverted position such that the person faces upward as they are pivoted. This often results in a situation where the person is pivoted in an uncontrolled manner which may result in injury as there is no fixed support structure within reach of the person as they are pivoted. This rearward rotation can also cause significant disorientation.
One inversion device known as the Bac-Trac, provides a frame which supports a lap pad above the ground for pivotal movement about a horizontal axis. In use, a person stands adjacent the frame such that the lap pad extends laterally across their waist. The person then pivots themselves forwardly with the pad about the horizontal axis while being supported entirely by the unstable mounted lap pad. A laterally extending safety bar is arranged to extend across the back of the person""s knees once the person has inverted themselves about the horizontal axis. The lap pad however, is arranged to pivot freely in either direction and requires significant strength and control on the part of the user to guide themselves through the inversion as the device provides no support to the person other than across the waist and across the back of the knees. This type of inversion is unsuitable for persons who are not already considerably fit.
According to one aspect of the present invention there is provided an inversion chair for inverting a person supported thereon, the chair comprising:
a frame;
a seat pivotally mounted on the frame for pivotal movement between an upright position and an inverted position in which the seat is substantially inverted relative to the upright position, the seat being arranged to support the person thereon;
a restraint coupled to the seat and being arranged to restrain the person within the seat as the seat is pivotally displaced from the upright position to the inverted position; and
a stop member restricting rearward pivotal rotation of the seat from the upright position to the inverted position;
whereby the seat rotates forwardly and faces downwardly as the seat is displaced from the upright position to the inverted position.
The inversion chair allows a person to be inverted from the upright position to the inverted position by pivoting the chair in a forward direction. By pivoting the chair forwardly, a fixed supporting structure such as the frame of the chair or the ground beneath the chair is within reach of the person in the chair during the entire movement between the upright and inverted positions. This allows the movement to be executed in a controlled manner for reducing possible risk of injury as a result of the chair tipping in an uncontrollable manner. Furthermore, forward rotation is a more natural movement that rearward rotation, resulting in less mental resistance to the inversion process and thus better relaxation is achieved for optimal results for both disabled and able bodied users.
There may be provided a locking member mounted on the frame arranged to engage the stop member, the locking member being selectively separable from the frame to permit displacement of the seat in both forward and rearward directions in relation to the frame when the locking member is removed.
Preferably there is provided various mounting locations for the locking member each corresponding to a relative orientation of the seat in relation to the frame.
For use as a rocking therapy, there may be provided a rearward locking member mounted on the frame arranged to engage the stop member in a reclined position in which the seat extends at a rearward incline in relation to the upright position and a forward locking member mounted on the frame arranged to engage the stop member in a forward inclined position in which the seat extends at a forward incline in relation to the upright position. The seat is thus arranged to pivot freely between the reclined position and the forward inclined position. Rocking therapy involves rocking forward and back to relieve the constant pressure on the spine.
To be used for drafting and the like, there may be provided a forward locking member mounted on the frame arrange to engage the stop member in a forward inclined position in which the seat extends at a forward incline in relation to the upright position, the locking member being arranged to restrict displacement of the seat in relation to the frame. A person may then be supported on the chair at a forward incline in relation to a substantially level table top. Additional restraints may be used for securing the legs and upper torso of the person in the chair when the seat is inclined forwardly when drafting and the like.
For use as an inversion chair, there may be provided an upper locking member mounted on the frame arranged to engage the stop member in the upright position for restricting rearward pivotal movement of the seat in the upright position and a lower locking member mounted on the frame arranged to engage the stop member in the inverted position for restricting rearward pivotal movement of the seat in the inverted position.
The frame preferably includes a lift mechanism arranged to raise the seat in the inverted position.
When the frame comprises a plurality of legs supporting the seat thereon, the lift mechanism preferably comprises an actuator associated with each leg for selectively extending a length of the leg to raise the seat. Alternatively, the pivot supporting the seat on the frame may be adjustable in relation to the ground by mounting the seat pivot on a track or the like which is supported on the frame. The seat may then be displaced vertically in relation to the frame which supports the seat above the ground.
A damper may be mounted between the seat and the frame for providing limited resistance to the relative pivotal movement therebetween.
The damper may comprise a pair of bushings pivotally supporting the seat on the frame. Suitable materials for the bushing include metal and carbon materials. Other forms of dampers may include fluid displacement type dampers and the like. A cam lock may also be provided for selecting the desired amount of resistance to pivotal movement. A damper would not be required in an automatically operated embodiment.
When using a damper in a manually operated embodiment, the seat is also preferably biased towards the upright position by a spring or other similar mechanism.
There may be provided a locking member arranged to secure the seat in the upright position.
The restraint preferably comprises a laterally extending support arranged to be secured across a lap of a person supported in the seat wherein the support includes an adjustable mounting mechanism arranged to mount the support at various spacings in relation to the seat.
A drive mechanism is preferably coupled between the seat and the frame controlling pivotal movement of the seat in relation to the frame. The drive mechanism preferably includes controls mounted on the seat which are arranged to be accessible to a person supported in the seat through a full range of motion of the seat in relation to the frame. The drive mechanism allows complete control of the inversion process by disabled persons without assistance or supervision being required. The drive mechanism preferably further includes an integral stop mechanism providing limits to the amount of rotation permitted and the direction of rotation permitted depending upon the angular position of the seat in relation to the frame.
The drive mechanism may include a seat lift mechanism arranged to raise the seat in the inverted position in relation to the upright position automatically as the seat is displaced between the upright position and the inverted position by the drive mechanism.
According to a further aspect of the present invention there is provided a method of inverting a person comprising;
providing a chair which is supported for pivotal movement about a substantially horizontal chair axis;
sitting the person on the chair to face in a forward direction;
restraining the person to the chair; and
pivoting the chair about the chair axis in the forward direction from an upright position to an inverted position in which the chair is inverted about the chair axis in relation to the upright position such that the person faces downwardly as the chair is pivoted.
The method preferably includes restricting pivotal movement of the chair in a rearward direction when the chair is in the upright position.
A damper on the chair may be used to partially resist pivotal movement of the chair.
Pivotal movement of the chair is preferably biased towards the upright position.
The method may further include lifting the chair before it is pivoted into the inverted position.
Locking the chair in the inverted position may be desirable for ensuring the person in the chair is supported in a stable manner in the inverted position.